In many cases, the commercial diver will be accompanied by a dive assistant (who may also be a certified commercial diver) and a dive operator. The dive assistant and dive operator remain above-water and manage the dive systems during the inspection. The dive operator provides direction and orientation to the diver, and can record the video. The dive assistant manages the diver's umbilical line, ensuring that the line always has the optimal amount of slack to prevent fouling. It may also be helpful to have personnel on hand who are familiar with the design of the underwater structures as well as the nature of the damage or defect being inspected in order to provide direction to the diver through the dive operator.

In addition to documenting damage and defects, the diver should be prepared to recover any detached components which can provide useful information regarding the stresses placed on the structure and causes of failure. The diver should also be on the lookout for conditions that present an immediate danger, such as potential structural failures. Depending on the capabilities of the diver, it may be possible to make temporary repairs to items that present an immediate danger.

A hard helmet equipped with a two-way intercom and camera allows the diver to communicate with those above the water during the inspection.

Establishing the protocols

Each claim will define the goals and parameters of a dive, but these actions will provide some guidance for most inspections.

1. Identify damaged or defective structures.

In claims that involve non-localized defects or damage (such as damage caused by a storm event), an inspection of all underwater components may be appropriate. In instances of localized defects or damage (such as damage caused by an impact), the inspection may be limited to the affected area. To identify the damage or defect, the diver will visually inspect the underwater components and spot check their structural integrity by hand. Prior to beginning the inspection, the diver should be thoroughly informed regarding the underwater structures, and the types of expected damage or defects, in order to ensure that the inspection is conducted as efficiently as possible.

2. Identify damage not obvious from above water inspection.

Damage events or localized defects can cause uneven stresses on marine structures. As a result, above-water components may sometimes be undamaged or only minimally damaged, while the underwater structures may absorb the majority of the force. Above water there may appear to be only minimal local damage with the structures appearing to be out-of-square. An underwater dive inspection will help determine the impact on the underwater structures and provide a clear view of the components.

3. Define the scope of repairs.

The dive inspection can also be used for developing a scope of repairs. The diver will need an understanding of potential repair methods and will likely engage in hands-on testing of the structure. Someone familiar with the design components, such as a structural engineer, should work in conjunction with the diver to ensure the structural testing and repair methodologies are sufficient. For example, in the case of a bent support structure, the diver may test the structure to determine if the damage can be repaired by only replacing the bent support member, or if additional attached components will also need to be replaced to ensure structural integrity.

4. Differentiate new damage from old.

In claims that involve older underwater structures and components, it is common to see damage that pre-dates the claim event. Therefore, it may be helpful for the inspection to focus on obtaining information to differentiate older damage from more recent damage. Newer breaks and bends in underwater metal structures may appear to be bright and shiny as compared to older damage that may appear to be dull, corroded and covered with debris.

5. Review construction and installation methods.

A dive inspection can be tailored to document construction and installation methods to gather information about factors that may have contributed to the claim. Instead of limiting the focus on the damage, the diver will document the components used in the structure and how they were assembled. The as-built structure can then be compared to the original blueprints and manufacturer's specifications. The information may have subrogation implications or may be relevant to the defense or prosecution of a construction defect claim.

For example, distance and angle of moorings can be checked to determine if the anchor locations meet the design specifications. Anchor mooring systems are typically designed such that each mooring works in conjunction with the remaining moorings to evenly spread the load across the moored structure. If any of the moorings are out of place, the load will not be evenly spread across the structure, which can lead to damage from even minor events which could have been avoided if the moorings were placed correctly.

The dive assistant and dive operator record video and manage the diver's air system.